flimsy

The story

The origin of the adjective is uncertain; it is possibly from flim(-flam) (“(noun) false information presented as true, misinformation, nonsense; poor attempt at deception, confidence trick, pretence; (adjective) frivolous, nonsensical; deceptive; fictitious”) or a metathesis of film (“thin layer of a substance; slender thread”) + -sy (suffix forming adjectives and nouns). The noun and verb are derived from the noun. Noun sense 4 (“metal container”) refers to the fact that the containers often split along their seams and leaked.

First known use, by meaning

• from 18th c. Likely to bend or break under pressure; easily damaged; frail, unsubstantial.
• from 18th c. Of clothing: very light and thin.
• from 18th c. Of an argument, explanation, etc.: ill-founded, unconvincing, weak; also, unimportant; paltry, trivial.
• from 19th c. Of a person: lacking depth of character or understanding; frivolous, superficial.
• 18th c. Of a person, their physical makeup, or their health: delicate, frail.