Pm
Pm
pm.
| an extraordinary or unusual thing, person, or event; an exceptional example or instance. |
| a gadget; dingus; thingumbob. |
p.m.
Based on the Random House Dictionary, © Random House, Inc. 2013.
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| pm1 | |
| —abbreviation for | |
| premium | |
| pm2 | |
| —the internet domain name for | |
| St Pierre and Miquelon | |
| Pm | |
| —the chemical symbol for | |
| promethium | |
| PM | |
| —abbreviation for | |
| 1. | Prime Minister |
| 2. | Past Master (of a fraternity) |
| 3. | Paymaster |
| 4. | Postmaster |
| 5. | military Provost Marshal |
| p.m., P.M., pm or PM | |
| —abbreviation for | |
| 1. | See a.m. (indicating the time period from midday to midnight) post meridiem |
| 2. | post-mortem (examination) |
| [(sense 1) Latin: after noon] | |
| P.M., P.M., pm or PM | |
| —abbreviation for | |
| [(sense 1) Latin: after noon] | |
| pm, P.M., pm or PM | |
| —abbreviation for | |
| [(sense 1) Latin: after noon] | |
| PM, P.M., pm or PM | |
| —abbreviation for | |
| [(sense 1) Latin: after noon] | |
| p.m., P.M., pm or PM | |
| —abbreviation for | |
| 1. | See a.m. (indicating the time period from midday to midnight) post meridiem |
| 2. | post-mortem (examination) |
| [(sense 1) Latin: after noon] | |
| P.M., P.M., pm or PM | |
| —abbreviation for | |
| [(sense 1) Latin: after noon] | |
| pm, P.M., pm or PM | |
| —abbreviation for | |
| [(sense 1) Latin: after noon] | |
| PM, P.M., pm or PM | |
| —abbreviation for | |
| [(sense 1) Latin: after noon] | |
| p.m., P.M., pm or PM | |
| —abbreviation for | |
| 1. | See a.m. (indicating the time period from midday to midnight) post meridiem |
| 2. | post-mortem (examination) |
| [(sense 1) Latin: after noon] | |
| P.M., P.M., pm or PM | |
| —abbreviation for | |
| [(sense 1) Latin: after noon] | |
| pm, P.M., pm or PM | |
| —abbreviation for | |
| [(sense 1) Latin: after noon] | |
| PM, P.M., pm or PM | |
| —abbreviation for | |
| [(sense 1) Latin: after noon] | |
| p.m., P.M., pm or PM | |
| —abbreviation for | |
| 1. | See a.m. (indicating the time period from midday to midnight) post meridiem |
| 2. | post-mortem (examination) |
| [(sense 1) Latin: after noon] | |
| P.M., P.M., pm or PM | |
| —abbreviation for | |
| [(sense 1) Latin: after noon] | |
| pm, P.M., pm or PM | |
| —abbreviation for | |
| [(sense 1) Latin: after noon] | |
| PM, P.M., pm or PM | |
| —abbreviation for | |
| [(sense 1) Latin: after noon] | |
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p.m.
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pm abbr.
picometer
Pm
The symbol for the element promethium.
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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| Pm
The symbol for promethium. |
promethium  (prə-mē'thē-əm) Pronunciation Key
Symbol Pm A radioactive metallic element of the lanthanide series. Promethium does not occur in nature but is prepared through the fission of uranium. It has 17 isotopes, one of which is used to make long-lived miniature batteries that work at extreme temperatures for up to five years. The longest-lived isotope, Pm 147, has a half-life of 2.5 years and is used as a source of beta rays. Atomic number 61; melting point 1,168°C; boiling point 2,460°C; valence 3. See Periodic Table. |
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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PM
/P-M/1. v. (from `preventive maintenance') To bring down a machine for inspection or test purposes. See provocative maintenance; see also scratch monkey.
2. n. Abbrev. for `Presentation Manager', an elephantine OS/2 graphical user interface.
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PM definition
1. preventive maintenance.
2. Presentation Manager
3. ["PM, A System for Polynomial Manipulations", G.E. Collins, CACM 9(8):578-589 (Aug 1966)].
[Jargon File]
pm
|
| pM picomolar |
| Pm promethium |
PM
|
pm.
|
| p.m. Latin post meridiem (after noon) |
| P.M. Latin post meridiem (after noon) |
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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pm
(Pm), chemical element, only rare-earth metal of transition Group IIIb of the periodic table not detected in nature. Conclusive chemical proof of the existence of promethium, the last of the rare-earth elements to be discovered, was obtained (1947) by J.A. Marinsky, L.E. Glendenin, and C.D. Coryell, who isolated the radioactive isotope promethium-147 (2.7-year half-life) from uranium fission products at the research site at Oak Ridge, Tenn. Identification was firmly established by spectroscopy. Earlier investigators thought that they had found the element with atomic number 61 in naturally occurring rare earths and had prematurely called it illinium and florentium. Promethium-147 is effectively separated from the other rare-earth fission products by an ion-exchange method. Its soft beta radiation is converted to electricity in miniature batteries formed by sandwiching promethium between wafers of a semiconductor such as silicon; these batteries operate in extreme temperatures for five years. Promethium has also been prepared by slow neutron bombardment of the isotope neodymium-146; the resultant isotope, neodymium-147, decays by electron emission to promethium-147. The metal itself was first prepared (1963) by reduction of the fluoride, PmF3, with lithium
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