Ultracrepidarian is an adjective that means expressing opinions outside of one's knowledge. It can also be used as a noun that refers to a person who expresses opinion outside of ones knowledge.

Our word of the day takes its origin from a Latin phrase that means ‘the cobbler should not judge beyond his shoe.’ Crepidam (CRAY pee dam) means ‘shoe.’ With ultracrpepidarian, the addition of the prefix U-L-T-R-A, meaning ‘beyond’ gets us ‘beyond one’s shoe’ or ‘beyond one’s area of expertise.’

The word may be used as an adjective to describe the act of seeing beyond one’s knowledge or it can be a noun that describes a person with the habit of doing so, for example: I don’t want to be an ultracrepidarian, but I feel there is no reason NASA shouldn’t send a man to mars. I may not be an expert on space, but I’ve seen enough space movies to know that this kind of thing would be perfectly safe.