to try (to do something) or make an effort to accomplish (something), esp without success

He attempted to swim across the swollen river

They should never have attempted the crossing in such weather

(often + at) the act or an instance of attempting something; esp an unsuccessful effort

her attempts at poetry

(often + on) an effort to conquer a mountain or record

an attempt on the summit

an attack or assault

He had survived three attempts on his life