late 14c., sentement, "personal experience, one's own feeling," from Old French santement, sentement (12c.) and directly from Medieval Latin sentimentum "feeling, affection, opinion," from Latin sentire "to feel" (see sense (n.)).
The original sense was obsolete after Middle English. From early 15c. as "intention, inclination." The meaning "what one feels about something, thought, opinion, notion" (1630s) and modern spelling seem to be a re-introduction from French (where it was spelled sentiment by 17c.).
In this sense a vogue word by mid-18c. with wide application, commonly "higher feeling, a thought colored by or proceeding from emotion," especially as expressed in literature or art (by 1709). The 17c. sense is preserved in phrases such as my sentiments exactly.
1749, "pertaining to or characterized by sentiment, appealing to sentiment rather than reason," from sentiment + -al (1). At first without pejorative connotations; the meaning "too tender-hearted, apt to be swayed by sentiment" is attested by 1768 (implied in sentimentality). The French word is said to be from English. Related: Sentimentally.
an exclamation conveying a sentiment of congratulation, 1630s, from congratulation (q.v.).
c. 1600, " parallel position," from Greek parallelismos, from parallelizein (see parallel). In literature, "correspondence resulting from repetition of the same sentiment, imagery, or construction" is from 1778.
1580s, "nobly brave or valiant," from magnanimity + -ous, or else from Latin magnanimus "highminded," literally "great-souled," from magnus "great" (from PIE root *meg- "great") + animus "mind, soul, spirit" (see animus). From 1590s as "elevated in soul or sentiment, superior to petty resentments." Related: Magnanimously.
1650s, in reference to ancient Greece, "a reciter of epic poems" (especially Homer's), from French rhapsodiste, from rhapsode, from Greek rhapsōdos "a rhapsodist" (see rhapsody). From 1741 as "one who uses rhapsodic language, one who speaks or writes with exaggerated sentiment or expression." For the classical sense, rhapsode later was used in English (1834).