BIL

1) See Basic Insulation Level. 2) See Basic Impulse Level.
Found on http://www.youngco.com/young2.asp?ID=4&Type=3

Bil

stock type bi-lavatory (1930s semi fast), all withdrawn
Found on http://www.encyclo.co.uk/local/21542

BIL

Brother-In-Law -or- Boss Is Listening
Found on http://www.netlingo.com/acronyms.php
No exact match found