Reluctance is unwillingness that shows in how slowly you act. You are doing it, and everybody can see you would rather not.
It takes to and a verb. The word describes visible hesitation rather than refusal, which is why it appears in phrases like with obvious reluctance and considerable reluctance. Formal writing uses it to explain a decision that was made late. The adjective reluctant is far commoner. Physics has an unrelated technical sense in magnetism, which almost nobody outside the subject ever meets.
1nounreluctanceUnwillingness to do something, shown in hesitation.
“He agreed, with obvious reluctance.”
Reluctance is a struggle. Latin reluctor joins re, back, to luctor, to wrestle, so a reluctant person is fighting the thing rather than merely declining it.
Latin
relū̆ctor — to struggle against, oppose, resist
English, today
reluctance
Built from
From reluct + -ance. From Latin relū̆ctor (“to struggle against, oppose, resist”) -ance, from re- (“back”) + luctor (“to struggle”).
Etymology from Wiktionary, CC BY-SA