From classical Japanese 探す (sagasu), derived from the root *saga-*, meaning to search, grope, or feel around. Related to 探る (saguru, "to probe/feel out"), which shares the same root and carries a more deliberate or investigative nuance. The kanji 探 (search, explore) also appears in 探偵 (tantei, detective) and 探険 (tanken, exploration).

In Japan, 探す is the everyday word for any kind of searching — a lost item, a job, a house, even love (恋人を探す, "looking for a partner"). It is distinct from 調べる (shiraberu), which means to investigate or look something up (like in a dictionary or database). Mixing the two is a common learner error: use 探す when something is physically missing or desired; use 調べる when gathering information.