noun
activity or excitement that is unusual and that often is not wanted or necessary [noncount]
an expression of anger or complaint especially about something that has little importance [noncount]
verb
fusses; fussed; fussing
[no obj]
to be or become upset or worried
In informal British English, someone who is not fussed is not bothered or worried.
US :to show that you are annoyed or unhappy
fuss over
[phrasal verb]
fuss over (someone or something) :to pay a lot of attention to (someone or something) in a nervous or excited way
fuss with
[phrasal verb]
fuss with (something) :to move or handle (something) in a nervous or uncertain way :to fiddle with (something)