'union-friendly' originates from the combination of 'union,' referring to labor unions, and 'friendly,' meaning supportive or favorable.

'Union' comes from the Latin word 'unio,' meaning 'oneness or unity,' and 'friendly' from Old English 'freondlic,' meaning 'kind or supportive.'

Initially, 'union' referred to any form of unity, but in modern usage, it often refers to labor unions. 'Friendly' has maintained its meaning of being supportive.