'dependably-equipped' is a compound of 'dependably' (the adverb form of 'dependable') and 'equipped' (the past participle of 'equip'). 'dependable' ultimately derives from Latin 'dependere', where 'de-' meant 'down' and 'pendere' meant 'to hang' (via Old French and Middle English). 'equip' comes from Old French 'esquiper' meaning 'to outfit'.

'dependably' developed from Middle English forms of 'depend' (from Latin 'dependere') into the adjective 'dependable' and then into the adverb with the suffix '-ly'; 'equipped' comes from Old French 'esquiper' which passed into Middle English as 'equip' and then formed the past participle 'equipped'.

Originally related to Latin senses of 'hanging' or 'relying' for 'depend-' and to 'outfitting' for 'equip'; over time 'depend-' produced senses of reliability ('dependable'), and 'equip' has remained close to its original meaning of providing gear or fitting out, so the compound now means 'reliably fitted out'.