regret, stinginess
慳 centers on a tight, unwilling attitude toward giving or spending: regret over loss and stinginess in holding back resources.
慳 combines 忄 (heart) with 堅, which likely contributes the sound and the idea of being firm or tight, suggesting a heart that is tight with resources.
The heart radical 忄 beside 堅 (firm, hard) paints a picture of a heart hardened against giving: stinginess and regret over what might be lost.
For ケン, imagine a stingy person named Ken who regrets every penny spent: Ken -> ケン, and his tight heart matches the kanji's meaning.
blunt; curt; brusque