having a lot of work to do

engaged, at work

(of a person) thinking of, paying attention to, what one does, says etc

cautious; painstaking

hard-working; showing care and effort

persevering, hard-working

extremely busy with and interested (in an activity, book etc)

preoccupied; attentive to

an apparatus for grinding

hardworking

willing to work long and hard

hardworking

very careful; thorough

meticulous, thorough

enjoying and wanting to study; very careful

scholarly, attentive

never coming to an end

certain, unchanging