tick vs mark off

tick is a noun but mark off is not a noun.

Word	Noun	Adjective	Verb	Adverb
tick	Yes	No	Yes	No
mark off	No	No	Yes	No

As verbs, tick and mark off are synonyms defined as:

Other synonyms of tick include check, check off, mark, tick off.

tick (noun)	mark off (noun)
any of two families of small parasitic arachnids with barbed proboscis; feed on blood of warm-blooded animals
a light mattress
a mark indicating that something has been noted or completed etc.
a metallic tapping sound

tick (verb)	mark off (verb)
put a check mark on or near or next to	set boundaries to and delimit
sew	put a check mark on or near or next to
make a clicking or ticking sound
make a sound like a clock or a timer