rub-n; 4 Senses

Sense Number 1: the act of wiping or massaging a surface

Commentary: RUB[+event][+action][+wiping][+of_surface]

She gave the counters a quick rub with a sponge.
He pulled out a towel and gave the wet dog a vigorous rub with it.

WordNet 3.0 Sense Numbers: 1

Sense Number 2: a circumstance which poses a significant hindrance

Commentary: RUB[+state][+circumstance][+hindrance][+significant]

That's the rub, we can't be at both meeting at the same time.
The rub was that John had not allowed himself enough time to write a comprehensive report on the project.

WordNet 3.0 Sense Numbers: 2

Sense Number 3: a therapeutic skin ointment

Commentary: RUB[+artifact][+ointment][+therapeutic][+skin]

She applied a vapor rub to the child's chest.
This cream is a muscle rub that helps soothe minor injuries.

WordNet 0.0 Sense Numbers: 1a

Sense Number 4: a dry spice mixture for seasoning meats

Commentary: RUB[+artifact][+ointment][+food][+mixture][+spice][+coating][+for_meat]

They put a chipotle-based rub on the fish before grilling it.
Mary creates her own rubs with dried herbs and spices.

WordNet 0.0 Sense Numbers: -