'comprehender' originates from Latin, specifically the word 'comprehendere', where the prefix 'com-' meant 'together' (or 'with') and 'prehendere' meant 'to seize'.

'comprehendere' passed into Middle English (via Old French 'comprendre' and Medieval Latin usage) as 'comprehend' (verb); the agentive suffix '-er' was later added in English to form 'comprehender' meaning 'one who comprehends'.

Initially it meant 'to seize or grasp' (often physically), but over time the sense shifted metaphorically to 'to grasp mentally' or 'to understand', which is the modern core meaning behind 'comprehender'.