| BL | Block | |
| B/L | Baseline | |
| B/L | Bilateral | |
|
| BL | Blind (flange) | |
| BL | Baseline | |
| BL | Blend | |
| BL | Black | |
| BL | Blue | |
| BL | Blessed (title of a beatified person) | |
| BL | Bilateral | |
| BL | British Library (London, England) | |
| BL | Basel-Landschaft (canton postcode, Switzerland) | |
| BL | Basel Land (Basel Country; Suisse Half Canton) | |
|
| BL | Blank | |
| BL | Boys' Life (Boy Scouts of America magazine) | |
| B/L | Bill of Lading | |
| BL | Boys' Love (anime) | |
| BL | Bloco (Portuguese: block; postal usage) | |
| BL | Barrel | |
| BL | Be Late | |
| BL | Bolivia | |
| BL | Blowing (METAR descriptor) | |
| BL | Blacklist | |
| Bl | Baltic (linguistics) | |
| BL | Bill of Lading | |
| BL | Bottom Line | |
| BL | Borderlands (gaming) | |
| BL | Backlash | |
| BL | Blake Lively (actress) | |
| BL | Black Love | |
| BL | Bin Laden | |
| BL | Bolton (postcode, United Kingdom) | |
| BL | Belluno (Veneto, Italy) | |
| BL | Blanking | |
| BL | Big Lots (retail store sales quantity) | |
| BL | Bale | |
| BL | Black Lotus (gaming; Magic The Gathering) | |
| BL | Bruce Lee | |
| BL | Boundary Layer | |
| BL | Blower | |
| B/L | Back Log | |
| BL | Body Language | |
| BL | Black Lagoon (Anime) | |
| BL | Boston Legal (US TV series) | |
| BL | Bad Luck (chat) | |
| BL | Backlit | |
| BL | Bachelor of Letters (Bachelor of Arts - Japan) | |
| BL | Buddy List | |
| BL | Building Line (construction) | |
| BL | Backlog | |
| BL | Big Leaf (plant physiology) | |
| BL | Bush League | |
| BL | Bud Light (beer) | |
| B/L | Battery Limit | |
| BL | British Leyland | |
| BL | Bell Labs (Bell Telephone Laboratories) | |
| BL | Business Logic | |
| BL | Blockland (gaming) | |
| BL | Belly Laugh | |
| BL | Burkitt's Lymphoma | |
| BL | Bart's and The London (School of Medicine and Dentistry, UK) | |
| BL | Beam Line | |
| BL | Bilinear | |
| BL | Burkitt Lymphoma | |
| BL | But Last (Hyper Logo command) | |
| BL | Blast Load | |
| BL | Bioluminescence | |
| BL | Black Lung (Social Security) | |
| B/L | Branched to Linear (ratio) | |
| BL | Body Lift (automotive) | |
| BL | Basal Lamina (biology) | |
| BL | Boylover (used by pedophiles) | |
| BL | Biosafety Level | |
| BL | Breech Loading | |
| BL | Bereichsleiter/In (German: Director General) | |
| BL | Budget Line | |
| BL | Breaking Load (engineering) | |
| BL | Bit Line (computer memory) | |
| BL | Bibliography of the Lepidoptera | |
| BL | Blood Lust (gaming) | |
| BL | Barrister-at-Law (UK) | |
| BL | Bonney Lake (Washington) | |
| BL | Battle Lab | |
| BL | Bikini-Line | |
| BL | Battle-Lemarie (wavelet families) | |
| BL | Bachelor of Law | |
| BL | Borderline Lepromatous (leprosy) | |
| BL | Big Log | |
| BL | Beta Lamda | |
| BL | Basic Load (ammunition) | |
| BL | Bolaffi (philatelic dealers) | |
| BL | Block Formatter | |
| BL | Biocontainment Level (US DoD) | |
| BL | Bishops Lydeard (UK railway station) | |
| BL | Bell Logger | |
| BL | Bats Left (baseball) | |
| BL | Beastlord (gaming, Everquest) | |
| BL | Battery Limit | |
| BL | Burnlist (social networking game) | |
| BL | Buried Layer | |
| BL | Bachelier en Loisirs (Bachelor of Leisure Studies) | |
| BL | Beauty Leopard (Geely sports car model) | |
| BL | Boys Latin School of Maryland (Baltimore) | |
| BL | Breadth-Length | |
| BL | Bronzen Leeuw (Dutch) | |
| BL | Butt Line | |
| BL | Buttock Line | |
| BL | Bend Loss | |
| BL | Binder Library | |
| BL | Broken Loop | |
| BL | Bombline | |
| BL | Beautiful Lineswoman (Seinfeld TV show) | |
| BL | Bridge Latch | |
| BL | Battle Laboratories | |
| B/L | Beals, Lalonde and Associates (Ottawa, ON, Canada consulting group) | |