Green’s Dictionary of Slang

1. the vagina.

1680		M. Stevenson Wits Paraphras’d 25: Which makes me wish thee in my Warren, / For fear the Burrough shou’d grow barren.
1784		Rambler’s Mag. Jan. 40/1: The said Sir C— W— shall be totaly expelled their lower houses, and declared him totally unqualified to be a candidate for any of their burrows.

2. (Aus.) a pocket.

1967		‘Whisper All Aussie Dictionary’ in Kings Cross Whisper (Sydney) xxxii 7/1: burrow: Pocket. ‘Get into your burrow’ is heard quite often among scallywags.
1983		R. Aven-Bray Ridgey-Didge Oz Jack Lang 9: He wasted no time in diving into his burrow and extracting his willy.