'lumber-related' is a modern English compound formed from 'lumber' + 'related'. 'lumber' originates from Middle English, specifically the word 'lumber' (used for bulky timber or goods), and 'related' comes from Latin via Old French ('relatus' / 'relater'), where the Latin root elements conveyed the idea of carrying back or bringing together.

'lumber' in Middle English meant bulky goods or timber and later came to be used specifically for timber (especially in North American English). 'related' developed from Latin 'relatus' through Old French 'relater' and Middle English 'relaten'; the compound 'lumber-related' arose in Modern English by straightforward compounding of the two words to describe things connected with lumber.

Initially, 'lumber' could mean bulky items, obstructions, or timber; over time it narrowed in many dialects to mean 'timber' or 'wood for building'. 'related' originally carried the sense of 'brought back' or 'told' in Latin-derived forms and evolved to mean 'connected to' in modern use; together the compound now means 'connected with timber or the timber industry.'