The term "demur" means to express disagreement or refuse to do something. It can also imply expressing doubt about or opposition to a plan or suggestion. In essence, when someone demurs, they are indicating a reluctance or hesitation regarding a particular action or decision.

verb
demur (verb) · demurs (third person present) · demurred (past tense) · demurred (past participle) · demurring (present participle)
raise doubts or objections or show reluctance:
"normally she would have accepted the challenge, but she demurred"

Similar:
object - protest - cavil - dissent - balk - hesitate - think twice - hang back - refuse - boggle - kick up a fuss - raise objections - take exception - take issue - lodge a protest - raise doubts - express doubt - express reluctance - express reservations - express misgivings - be unwilling - be reluctant - drag one's heels - be cagey - kick up a stink - law - dated - put forward a demurrer.

noun
demur (noun)
the action or process of objecting to or hesitating over something:
"they accepted this ruling without demur"

Similar:
objection - protest - protestation - complaint - dispute - dissent - carping - cavilling - recalcitrance - opposition - resistance - reservation - hesitation - reluctance - unwillingness - disinclination - doubts - qualms - misgivings - second thoughts - a word - niggling - griping - grousing - boggling - demurrers - demurral - lack of enthusiasm - a murmur - a peep - a sound.

Origin
Middle English (in the sense ‘linger, delay’): from Old French demourer (verb), demeure (noun), based on Latin de- ‘away, completely’ + morari ‘delay’.