notion-n; 3 Senses

Sense Number 1: a mental conception or idea about something

Commentary: NOTION[+state][+mental][+conception] [+entity][+abstract][+information][+idea]

Different societies have differing notions about the roles of men and women.
I have no notion of where I may have left my keys.
It's an interesting notion, but can it be tested experimentally?

WordNet 3.0 Sense Numbers: 1, 2, 3

Sense Number 2: a sudden emotional impulse

Commentary: NOTION[+state][+emotional][+desire][+impulse]

In the middle of the meeting we suddenly developed the notion to order a pizza.
John acted on his notion to jump into the ocean for a morning swim.

WordNet 0.0 Sense Numbers: 2

Sense Number 3: small personal items, sundries

Commentary: NOTION[+entity][+group][+artifact][+small][+personal][+sundries]
NOTE: usually occurs in the plural form

Jane bought small bottles of shampoo and rinse at the notions counter.
Needle and thread are useful notions to have when you travel.

WordNet 3.0 Sense Numbers: 4