1851, "capable of being influenced," from suggest + -ible. Meaning "that can be suggested" is from 1836. Related: Suggestibly; suggestibility.
Entries linking to suggestible
suggest v.
1520s, "place before another's mind; put forward a proposition," from Latin suggestus, past participle of suggerere "bring up, bring under, lay beneath; furnish, afford, supply; prompt" (see suggestion). Meaning "to act so as to call up the idea of (something else)" is from 1709. Related: Suggested; suggesting.
-ible
word-forming element making adjectives from verbs, borrowed in Middle English from Old French -ible and directly from Latin adjective suffix -ibilis (properly -bilis); see -able.