From Wiktionary, the free dictionary
From the contraction of final き (ki) in the 連体形 (rentaikei) forms of ク活用 (ku-katsuyō) and シク活用 (shiku-katsuyō) adjectives with earlier 所 (aku).
けく • (-keku)
- Synonym of く (“nominalization suffix”)
- This form is used after the basic non-inflected stem of ク活用 (ku-katsuyō) and シク活用 (shiku-katsuyō) adjectives; e.g. 安けく (yasukeku), 悲しけく (kanashikeku).