HLL /H-L-L/ n. [High-Level Language (as opposed to assembler)] Found
   primarily in email and news rather than speech. Rarely, the variants
   `VHLL' and `MLL' are found. VHLL stands for `Very-High-Level Language'
   and is used to describe a {bondage-and-discipline language} that the
   speaker happens to like; Prolog and Backus's FP are often called VHLLs.
   `MLL' stands for `Medium-Level Language' and is sometimes used
   half-jokingly to describe {C}, alluding to its `structured-assembler'
   image. See also {languages of choice}.


Source: The Jargon File

HLL
     High Level Language
     
     
Source: Virtual Entity of Relevant Acronyms