痕 - mark, foot print

bloodstain

trace; vestige; mark; sign; evidence

vestigial (rudimentary) organ

glacial striae; glacial striations; glacial grooves

skid mark; tire mark; tyre mark

tracer bullet; tracer shell

stria (carved out by a glacier, etc.)

brake marks; skid marks

injection scar (e.g. injected drugs)

fingernail mark; scratch

feeding signs (of an animal, e.g. teeth marks in nuts, holes in leaves)

bullet hole; gunshot wound