First recorded in 1960–65.
Comes from petro-, a combining form meaning \"rock,\" and ichor, which in classical mythology means “ethereal fluid flowing in the veins of the gods.”
Sign up for more Word of the Day!

\r\nEXAMPLES OF PETRICHOR\r\n

The desert landscape was quickly transformed as petrichor filled the air after a long-awaited rainstorm.
As the storm passed, leaving behind puddles and damp earth, the sweet petrichor lingered like a fond memory.

\r\nIt's National Poetry Month, and we’ve created a challenge that really is for everyone. Submit now!","audio":"https://static.sfdict.com/audio/NEW2016/petrichor_000.mp3","definitions":[{"partofspeech":"noun","data":"a distinctive scent, usually described as earthy, pleasant, or sweet, produced by rainfall on very dry ground."}],"examples":[],"imageUrl":"https://www.dictionary.com/e/wp-content/uploads/2024/03/petrichor_IG.png","accentColor":"#0063D7"}},"status":"succeeded"}},"meta":{"requestId":"-4HXqLvOTeU99a-tZCaMf","requestStatus":"fulfilled"}},{"type":"fetchWordsNearby/fulfilled","payload":{"data":{"before":[{"slug":"formularize","entry":"formularize"},{"slug":"formulary","entry":"formulary"},{"slug":"formulate","entry":"formulate"},{"slug":"formulation","entry":"formulation"},{"slug":"formula-unit","entry":"formula unit"}],"after":[{"slug":"formulism","entry":"formulism"},{"slug":"formulize","entry":"formulize"},{"slug":"form-word","entry":"form word"},{"slug":"formwork","entry":"formwork"},{"slug":"formyl","entry":"formyl"}]}},"meta":{"arg":{"word":"formula-weight"},"requestId":"YfxeMgcTeGAqT_q8zy-C7","requestStatus":"fulfilled"}},{"type":"luna/fetchExampleSentences/fulfilled","payload":{"data":{"tdb":[],"gbg":[]}},"meta":{"arg":{"word":"formula-weight"},"requestId":"djOaLN8oN_B3r_g1HoJJj","requestStatus":"fulfilled"}},{"type":"fetchDictionaryResults/fulfilled","payload":{"slugs":[{"entries":[{"__typename":"Entry","audioPronunciations":[],"confusableNotes":[],"genderNotes":[],"grammarNotes":[],"headword":{"displayForm":"formula weight","slug":"formula-weight"},"idioms":[],"orderKey":99999010,"ordinal":10,"origin":null,"partOfSpeechBlock":[{"definitions":[{"antonymsConnection":{"edges":[]},"definitionSetChunks":"[{\"type\": \"def\", \"children\": [{\"text\": \"(of a molecule)\", \"type\": \"text\"}, {\"type\": \"cross_reference\", \"punc\": \"stop\", \"children\": [{\"text\": \"molecular weight\", \"type\": \"text\"}], \"slug\": \"molecular-weight\", \"trailingSpace\": true}]}]","examples":[],"ordinal":1,"subdefinitions":[],"synonymsConnection":{"edges":[]}},{"antonymsConnection":{"edges":[]},"definitionSetChunks":"[{\"type\": \"def\", \"children\": [{\"text\": \"(of an ionic compound that does not form molecules) the sum of the atomic weights of the atoms of the formula unit.\", \"type\": \"text\"}]}]","examples":[],"ordinal":2,"subdefinitions":[],"synonymsConnection":{"edges":[]}}],"inflectionSets":[],"labelSet":{"labelSetText":"Chemistry."},"ordinal":1,"partOfSpeech":"noun"}],"pronunciationNotes":[],"pronunciationSet":null,"relatedFormSets":[],"sensitiveNotes":[],"spellingNotes":[],"synonymStudy":[],"usageAlerts":[],"usageNotes":[],"variants":[],"verbPhrases":[]}],"url":"formula-weight"}]},"meta":{"arg":{"slug":"formula-weight"},"requestId":"iOsAt4p3P1BULRbf1wkQL","requestStatus":"fulfilled"}},{"type":"fetchResultsData/fulfilled","payload":{"data":{"url":"formula-weight","displayForm":"formula weight","canonicalSlug":"formula-weight","content":[{"source":"luna","entries":[{"id":"u3bb48a285cbafaf0.-3bc55cee.14d9e67085f.20a8","type":"normal","entry":"formula weight","entrySyllabified":"formula weight","entryVariants":[],"homograph":null,"pronunciation":null,"predefinitionContent":"","posBlocks":[{"definitions":[{"order":1,"type":"simple","predefinitionContent":"","postdefinitionContent":"","definition":"(of a molecule) molecular weight. ","synonyms":"","antonyms":"","cites":[]},{"order":2,"type":"simple","predefinitionContent":"","postdefinitionContent":"","definition":"(of an ionic compound that does not form molecules) the sum of the atomic weights of the atoms of the formula unit.","synonyms":"","antonyms":"","cites":[]}],"pos":"noun","posSupplementaryInfo":"Chemistry."}],"origin":null,"originData":null,"supplementaryNotes":[],"variantForms":[],"variantSpellings":[],"referenceData":[],"relatedForms":[],"confusables":[]}]}],"nearbyWordOrdinal":59536,"index-rank-01":["formula weight"],"index-rank-02":[],"index-rank-03":[],"index-rank-04":["formula weight's","formula weights","formula weights'"],"index-rank-05":[],"index-rank-06":[],"index-rank-07":[],"index-rank-08":[],"index-rank-09":[],"index-rank-10":[],"index-rank-11":[],"index-rank-12":[],"index-rank-13":[],"index-rank-14":[],"index-rank-15":[],"categoryId":"339","complexityScore":0.2491333099192933,"gradeLevel":"high_school","tunaSlug":null,"isFeaturedMetaSlug":false}},"meta":{"arg":{"word":"formula-weight"},"requestId":"eKdTg4eITqX5YtsDUpiV1","requestStatus":"fulfilled"}},{"type":"fetchSpellSuggestions/fulfilled","payload":{"data":{"luna":[],"tuna":[],"lunaWithSlug":[],"tunaWithSlug":[]}},"meta":{"arg":{"word":"formula-weight"},"requestId":"3KWnCqht2-rnM9ycfoFCl","requestStatus":"fulfilled"}}]},"actionData":null,"errors":null}

formula weight

noun

Word of the Day