Entries linking to loathsome
Old English lað "hated; hateful; hostile; repulsive," from Proto-Germanic *laitha- (source also of Old Saxon leth, Old Frisian leed "loathsome," Old Norse leiðr "hateful, hostile, loathed;" Middle Dutch lelijc, Dutch leelijk "ugly;" Old High German leid "sorrowful, hateful, offensive, grievous," German leid "hateful, painful"), from PIE root *leit- (1) "to detest."
And niðful neddre, loð an liðer, sal gliden on hise brest neðer [Middle English Genesis and Exodus, c. 1250]
Weakened meaning "averse, disinclined" is attested from late 14c. "Rare in 17th and 18th cents.; revived in the 19th c. as a literary word" [OED]. Loath to depart, a line from some long-forgotten song, is recorded since 1580s as a generic term expressive of any tune played at farewells, the sailing of a ship, etc. French laid, Italian laido "ugly" are from the same Germanic source. The sense "ugly" persisted in English into 15c. in the marriage service, where a man took his wife for fayrer, for layther. Related: Loathness.
word-forming element used in making adjectives from nouns or adjectives (and sometimes verbs) and meaning "tending to; causing; to a considerable degree," from Old English -sum, identical with some, from PIE root *sem- (1) "one; as one, together with." Cognate with Old Frisian -sum, German -sam, Old Norse -samr; also related to same. "It usually indicates the possession of a considerable degree of the quality named: as mettlesome, full of mettle or spirit; gladsome, very glad or joyous" [Century Dictionary]. For the -some used with numbers (twosome, foursome, etc.), see -some (2).