One who delves, as a tiller of the ground, or excavator.

One who finds out or tries to find out by search or examination. Obsolete.

? A curious investigator.

One who seeks, in various senses of the verb; a searcher, an explorer, one who endeavours to find something hidden or lost. Const. as the verb…

An animal or person that burrows. (literal and figurative.)

A person employed to undertake research, esp. in an academic or scientific institution.

= researcher, n.