Seeker

wiktionary

ref

From Middle English sekar, sekere (also sechar, sechere), equivalent to seek +‎ -er. Compare Saterland Frisian Säiker(“seeker”), West Frisian syker(“seeker”), Dutch zoeker(“seeker”), German Low German Söker(“seeker”), German Sucher(“seeker”).

etymonline

ref

seeker (n.)

early 14c., agent noun from seek. The religious sect of the Seekers is attested from 1645.