Ignorance. It is not a contraction, but I suppose that some people, unfamiliar with the -t suffix (learnt, spelt, meant, etc), think there's a letter missing.
There IS a contraction. There IS a missing letter (althouth 'spelt' IS spelled 'spelled' with no contraction) and 'learning not' and 'meaning not' has no meaning for 'the ignorant' (you, maybe?). Lighten up and get with it! English is variable. And up for adaption.
Meant is a hold over from middle English. It is not a contraction, and adaptability aside, the English language is mutilated all the time by people. So to set the record straight, it may have been a contraction in Middle English, but basically it's considered a hold over and there is no mean't!! That would be an incorrect spelling.
The only place I can think of that you could find a legitimate use of mean't would be in verse by someone such as Shakespeare for the purpose of meter ['mean it']. And even then I'm not sure it would be written as one word.