expression
extraordinarily; uncommonly; exceptionally
Used adverbially to emphasize that something is far beyond the ordinary or average level. Often modifies adjectives or verbs.
彼は並外れて記憶力がいい。
He has an extraordinarily good memory.
今年の夏は並外れて暑かった。
This summer was exceptionally hot.
並外れた is the prenominal form used as an adjective (e.g., 並外れた才能), while 並外れて is the adverbial form.
From 並 (なみ, 'average, ordinary') + 外れて (はずれて, the te-form of 外れる 'to deviate, be off'). Literally 'deviating from the ordinary'.