1. (

• detect ,
• observe ,
• find ,
• discover ,
• notice ,

) discover or determine the existence, presence, or fact of; "She detected high levels of lead in her drinking water"; "We found traces of lead in the paint" ;

2. (

• notice ,
• mark ,
• note

) notice or perceive; "She noted that someone was following her"; "mark my words" ;

3. (

• comment ,
• notice ,
• remark ,
• point_out ,

) make or write a comment on; "he commented the paper of his colleague" ;

4. (

• notice ,
• acknowledge ,

) express recognition of the presence or existence of, or acquaintance with; "He never acknowledges his colleagues when they run into him in the hallway"; "She acknowledged his complement with a smile"; "it is important to acknowledge the work of others in one's own writing" ;