An over-credulous person was a "sucher" since the day she had written it so.
Old English swylc, swilc from a Proto-Germanic compound *swalikaz "so formed" (cf. Old Saxon sulik, Old Norse slikr, Old Frisian selik, Middle Dutch selc, Dutch zulk, Old High German sulih, German solch, Gothic swaleiks), from swa "so" (see so) + *likan "form," source of Old English gelic "similar" (see like). Colloquial suchlike (early 15c.) is pleonastic.