painless

adjectives

requiring little hard work or exertion
"a painless solution to the problem"
is similar to
posing no difficulty; requiring little effort
"an easy job"; "an easy problem"; "an easy victory"; "the house is easy to heat"; "satisfied with easy answers"; "took the easy way out of his dilemma"
not causing physical or psychological pain
"painless dentistry"
antonym
is similar to
not accompanied by pain sensations
"pain-free surgery"
see also
not causing or capable of causing harm
"harmless bacteria"; "rendered the bomb harmless"