AÎ

The letter combination aî represents the stressed sound /ɛr/.
It's typically found in nouns and adjectives where the stem ends in -aire.

E.g.
to compare, the comparison, comparable, comparative [Modern English]
ta compaire, þe compaîasson, compaîable, compaîatif [Inglish]

to bear, bearable [Modern English]
ta baire, baîable [Inglish]

to wear, wearable [Modern English]
ta ɯaire, ɯaîable [Inglish]




Citations:
https://www.etymonline.com/word/compare#etymonline_v_28450
https://www.oed.com/dictionary/compare_v1?tab=factsheet#8798097
https://www.etymonline.com/word/comparison#etymonline_v_17255
https://www.oed.com/dictionary/comparison_n?tab=factsheet#8798877
https://www.etymonline.com/word/comparable#etymonline_v_28449
https://www.oed.com/dictionary/comparable_adj?tab=factsheet#8796237
https://www.etymonline.com/word/comparative#etymonline_v_28456
https://www.oed.com/dictionary/comparative_adj?tab=factsheet#8796842

https://www.etymonline.com/word/bear#etymonline_v_8203
https://www.oed.com/dictionary/bear_v1?tab=meaning_and_use#25248525
https://www.etymonline.com/word/bearable#etymonline_v_29878
https://www.oed.com/dictionary/bearable_adj?tab=factsheet#25263140

https://www.etymonline.com/word/wear#etymonline_v_4874
https://www.oed.com/dictionary/wear_v1?tab=factsheet#15155146
https://www.oed.com/dictionary/wearable_adj?tab=factsheet#14774017