Webster's Revised Unabridged Dictionary · 1913

Shug

Shug , intransitive verb

[Compare Shrug.]

1.
To writhe the body so as to produce friction against one's clothes, as do those who have the itch. [Provincial English] — Halliwell
2.
Hence, to crawl; to sneak. [Obsolete]
There I 'll shug in and get a noble countenance. — Ford