'anal-retentiveness' is formed in English from the adjective 'anal-retentive' plus the noun-forming suffix '-ness'. 'anal' ultimately traces to Latin 'anus' meaning 'ring; anus', and 'retentive' comes from Latin 'retentivus' from 'retinēre' (re- 'back' + tenēre 'to hold').

'retentive' comes from Latin 'retinēre' → Late Latin/Medieval Latin 'retentivus' → Middle English forms 'retene/retine' and later Modern English 'retain/retentive'; 'anal' entered English from New Latin/medical usage based on Latin 'anus'. The compound 'anal-retentive' arose in 20th-century psychological discourse (Freudian terminology) and '-ness' was later added to form the abstract noun.

Originally 'anal' referred anatomically to the anus; in psychoanalytic theory 'anal-retentive' described personality traits supposedly stemming from the anal psychosexual stage (holding on, stinginess, orderliness). Over time the compound's common meaning shifted to the general sense of extreme orderliness, meticulousness, or obsessiveness.