stealth, steal, secret, private, hushed
窃 centers on acting in a hidden, quiet way to avoid notice: stealing, being secretive, or keeping something private and hushed.
窃 combines 穴 (cave, hole) with 切 (cut), suggesting the idea of cutting into a hidden place or acting stealthily. The exact historical development is uncertain, but the modern form supports the stealth meaning.
Picture a thief cutting 切 into a dark cave 穴 to steal something quietly. The hidden cave and the cutting action together mean stealth and secrecy.
For セツ, imagine a thief stealing a set of jewels from a cave: set -> セツ, and the theft is done in secret.
theft; stealing; larceny
plagiarism
theft; stealing; larceny
identity theft
identity theft
bicycle theft
using without permission; using information obtained in the course of one's duties
group of thieves
kleptomania
theft; stealing; larceny
kleptomania; kleptomaniac
kleptomania
kleptomania
(crime of) theft; (crime of) stealing; larceny
theft; act of larceny
peeping at (without permission)
voyeurism; scopophilia; scoptophilia
sneak-thief