Difference between Thumb and Pollex

Thumb

Part of speech: noun

Definition: The short thick digit of the hand that for humans has the most mobility and can be made to oppose (moved to touch) all of the other fingers. The part of a slider that may be moved linearly along the slider. (Abbreviation of) thumbnail (picture).

Part of speech: verb

Definition: To touch with the thumb. To turn the pages of (a book) in order to read it cursorily.

Example sentence: Start with God - the first step in learning is bowing down to God; only fools thumb their noses at such wisdom and learning.

Pollex

Part of speech: noun

Definition: The first, or preaxial, digit of the fore limb, corresponding to the hallux in the hind limb; the thumb. In birds, the pollex is the joint which bears the bastard wing.