sign up, to enlist, as in an organization or group; to register or subscribe: to sign up for the navy; to sign up for class.
Origin: 1175–1225; (noun) Middle English signe < Old French < Latin signum mark, sign, ensign, signal, image; (v.) Middle English signen to mark with a sign, especially the sign of the cross < Old French signer < Latin signāre to mark with a sign, inscribe, affix a seal to, derivative of signum
Related forms
sign·less, adjective
sign·like, adjective
post·sign, verb (used with object)
un·signed, adjective
Can be confused:sign, sing (see synonym note at the current entry).
Synonyms 1. trace, hint, suggestion. 1, 4. signal. 10. indication, hint, augury. Sign,omen,portent name that which gives evidence of a future event. Sign is a general word for whatever gives evidence of an event—past, present, or future: Dark clouds are a sign of rain or snow. An omen is an augury or warning of things to come; it is used only of the future, in general, as good or bad: birds of evil omen. Portent, limited, like omen, to prophecy of the future, may be used of a specific event, usually a misfortune: portents of war.
c.1300, "to make the sign of the cross," from O.Fr. signer, from L. signare, from signum (see sign (n.)). Sense of "to mark, stamp" is attested from mid-14c.; that of "to affix one's name" is from late 15c. Meaning "to communicate by sign language" is recorded from 1700.
A body manifestation, usually detected on physical examination or through laboratory tests or xrays, that indicates the presence of abnormality or disease. Compare symptom.