'hypothalamic' originates from New Latin, specifically the word 'hypothalamicus', where 'hypo-' meant 'under' and 'thalamos' (from Greek) meant 'chamber' (referring to the thalamus).

'hypothalamic' changed from New Latin 'hypothalamicus', which in turn derived from Greek components (hypo- + thalamos) and the anatomical New Latin 'hypothalamus'; it eventually entered English as the adjective 'hypothalamic'.

Initially it signified the position 'under the thalamus' (an anatomical descriptor); over time it came to mean 'relating to the hypothalamus' in biological and medical usage.