unalloyed

US /ˌʌn.əˈlɔɪd/
UK /ˌʌn.əˈlɔɪd/
1.

không hợp kim

(especially of a positive feeling) not spoiled by any amount of negative feeling; pure:

:
Spending time with one's family is never an unalloyed pleasure (= there are bad things about it too).