are

Etymology 1

From Middle English aren, from Old English earun, earon (“are”), reinforced by Old Norse plural forms in er- (displacing alternative Old English sind and bēoþ), from Proto-Germanic *arun (“(they) are”), from Proto-Germanic *esi/*izi (a form of Proto-Germanic *wesaną (“to be”)), from Proto-Indo-European *h₁ésti (“is”). Cognate with Old Norse eru (“(they) are”) (> Icelandic eru (“(they) are”), Swedish äro (“(they) are”), Danish er (“(they) are”)), Old English eart (“(thou) art”). More at art.

verb

1. second-person singular simple present of be
   Mary, where are you going?
2. first-person plural simple present of be
   We are not coming.
   Here we are! Audio (US) (file) 2016, VOA Learning English (public domain)
3. second-person plural simple present of be
   Mary and John, are you listening?
4. third-person plural simple present of be
   They are here somewhere.
5. (East Yorkshire, Midlands) present of be

Etymology 2

From French are.

noun

1. (rare) An accepted (but deprecated and rarely used) <a href="/dictionary/word/metric">metrica> unit of area equal to 100 square metres, or a former unit of approximately the same extent. Symbol: a.

Etymology 3

From the phonetic similarity between our and are in many English dialects (both /ɑː(ɹ)/).

det

1. (UK, US) Misspelling of our.