～だけ
～だけ · ～dake · JLPT N5 · noun
only ~
dake sounds like the K: just the K, only the K, nothing else
だけ comes from 丈 (take), meaning height or extent. It marks the full extent of something and no more, which gives only ~ and just ~. The same extent sense gives as ~, as in できるだけ: to the extent one can, as much as possible.