啻
シ, ただ.ならぬ, ただ.に
incomparable, merely
JLPT0 G13 S0 F5000
As per 帝# (unify) + 口 mouth → adverb inflecting the tone of voice to suggest *only* (← united; no other) → *merely*. A variant form, 啇, appears in many derivative characters, including 適, 摘, 滴 and 嫡.
[Full Kanji Etymology List]