'breakdown-related' is a compound formed from the noun 'breakdown' and the adjective 'related'. 'breakdown' originates from English compounding of 'break' + 'down' (where 'break' comes from Old English 'brecan' meaning 'to break' and 'down' from Old English 'dūn' meaning 'downwards/direction'), and 'related' comes from Latin 'relatus', the past participle of 'referre' (re- 'back' + ferre 'to carry'), via Old French and Middle English.

'break' originates in Old English 'brecan' and evolved into Modern English 'break'; 'down' as a directional adverb developed in Old English and combined with 'break' to form the compound noun 'breakdown' in modern usage; 'relate' comes from Latin 'relatus' through Medieval Latin/Old French into Middle English, producing the adjective 'related'. The compound 'breakdown-related' is a modern combination used to describe things connected to a breakdown.

Initially the separate elements referred to literal 'breaking' and direction 'down' and to 'being related/carried back' in Latin; over time the noun 'breakdown' came to mean 'failure or collapse' (including mechanical or psychological), and 'related' kept the sense 'connected to', so the compound's current meaning is 'connected to a failure/collapse'.