/əˈlaʊ/
[verb] To give permission for something to happen, or to make it possible for someone to do something. It can also mean to accept or admit that something is true or valid.
Two completely opposite Latin roots — one meaning 'to praise' and one meaning 'to calculate' — fused together in medieval French to create the single word we use today.
The word 'allow' carries a hidden split personality, born from two distinct Latin ancestors that collided inside Old French and emerged as something entirely new. The first parent is the Latin word 'allaudare', meaning 'to praise' or 'to approve', built from the prefix 'ad-' (meaning 'to' or 'toward') joined to 'laudare' (meaning 'to praise'), which also gave us the English words 'laud' and 'laudable'. The second parent is the medieval Latin 'allocare', meaning 'to place' or 'to assign', formed from 'ad-' plus 'locare' (meaning 'to place'), which itself descended from 'locus', meaning 'place' — a root that also produced 'location' and 'local'.
These two Latin streams flowed into Old French and merged into a single verb: 'alouer'. In Old French, 'alouer' carried the senses of both its ancestors simultaneously — it could mean 'to approve', 'to praise', or 'to assign and allocate'. Medieval French scribes and speakers did not treat these as separate words at all, and so the meanings quietly blended together over time into one rich, flexible verb.
English borrowed 'alouer' directly from Old French during the 14th century, reshaping it as 'allouen' and later 'allow'. Middle English writers used it in both streams of meaning — you could 'allow' an expense in the sense of accepting it as legitimate in an account book, and you could 'allow' an action in the sense of approving or permitting it. These two uses — the financial and the moral — sat comfortably side by side for centuries in legal, commercial, and everyday writing.
Over the following centuries, the accounting and financial sense gradually faded from everyday speech, though it survived in phrases like 'making allowances' and in legal writing. The dominant meaning shifted steadily toward permission — to allow something came to mean simply to let it happen, to not stand in its way. This is the core meaning most speakers reach for today: a parent allows a child to stay up late; a rule allows certain exceptions.
What makes 'allow' quietly remarkable is that its comfortable, everyday feel conceals this rich double ancestry. When we say someone 'allows' a request, we are unknowingly echoing both a Roman accountant calculating what expenses could be legitimately placed in a ledger, and a Roman orator praising something as worthy and approved. The word is, in a sense, both a green light and a round of applause compressed into two syllables.