mid-14c., "clasp in the arms," from Old French embracier (12c., Modern French embrasser) "clasp in the arms, enclose; covet, handle, cope with," from assimilated form of en- "in" (see en- (1)) + brace, braz "the arms," from Latin bracchium (neuter plural brachia) "an arm, a forearm," from Greek brakhion "an arm" (see brachio-). Related: Embraced; embracing; embraceable. Replaced Old English clyppan (see clip (v.2)), also fæðm (see fathom (v.)). Sexual sense is from 1590s.

1630s, figurative, "capable of being comprehended; that may be sounded by thought;" 1690s, literal, "capable of being sounded by measurement;" from fathom (v.) + -able.

1630s, literal ("bottomless"); 1640s, figurative ("not to be comprehended"); from fathom + -less.

"not sounded, not to be sounded," 1620s, from un- (1) "not" + past participle of fathom (v.).

*petə-, Proto-Indo-European root meaning "to spread."

It might form all or part of: compass; El Paso; expand; expanse; expansion; expansive; fathom; pace (n.); paella; pan (n.); pandiculation; pas; pass; passe; passim; passacaglia; passage; passenger; passport; paten; patent; patina; petal; spandrel; spawn.

It might also be the source of: Greek petannynai "to spread out," petalon "a leaf," patane "plate, dish;" Old Norse faðmr "embrace, bosom," Old English fæðm "embrace, bosom, fathom," Old Saxon fathmos "the outstretched arms."