From Middle English shuggen, shoggen, schoggen (“to shake, shake off, mix by shaking, tremble, shake loose from one's clothing”), probably a variant of Middle English schokken (“to move rapidly, shake, push”), from Middle Low German schocken (“to shake, tremble”). See schokken.
Meanings
(UK, dialectal, obsolete) To writhe the body so as to produce friction against one's clothes, as do those who have the itch.
the Comtesse Leinsengen again shugged her shoulders , drew her shawl around her , and was preparing to depart 1830, Lady Charlotte Campbell Bury, The Exclusives:
(UK, dialectal, obsolete) To crawl; to sneak.
There I'll shug in and get a noble countenance. 1621, John Ford, Thomas Dekker, William Rowley, The Witch of Edmonton: