haste + -en

source: [はたらく魔王さま!の真奥貞夫が急いで階段を駆け下りるGIF画像｜無料GIF画像検索 GIFMAGAZINE 668472]

verb no object, with infinitive

be quick to do something:

〖～ to do〗 急いで…する

e.g. he hastened to refute the assertion.

with adverbial of direction move or travel hurriedly:

｟かたく｠ ; 〖～＋副詞〗 〈人が〉急ぐ, 急いで行く (!〖副詞〗は方向の表現; hurryよりかたい語)

e.g. we hastened back to Paris.

with object cause (something) to happen sooner than it otherwise would:

〈人･物･事が〉〈人〉を急がせる, せきたてる; 〈事〉の速度を速める, 時期を早める(↔ delay)

e.g. a move that could hasten peace talks.

mid 16th century: extended form of haste, on the pattern of verbs in -en1.