rustic, crude
畯 centers on a lack of refinement: something rustic, crude, or unsophisticated, often associated with rural simplicity.
畯 combines 田 (field) with 夋, which likely contributes the sound. The exact historical development is uncertain, but the character is associated with rustic or crude qualities, possibly from a connection to rural fields.
A field (田) with a rough, unfinished-looking right side (夋) suggests something unpolished and rural: a rustic, crude scene.
For シュン, imagine a rustic farmer named Shun working in the field: Shun -> シュン, and his crude tools match the kanji's meaning.