If you do not internet search, you will see that comment out is the common term. Compare:
auskommentieren Vb. (comment out)
Das vorübergehende Deaktivieren einer oder mehrerer Zeilen eines Quellcodes, indem diese in Kommentaranweisungen eingeschlossen werden. ® siehe auch bedingte Kompilierung, Kommentar, verschachteln. (Microsoft Lexikon)
http://www.smilla.net/smillacomputing/pclexikon/

and

comment out
comment out vt. To surround a section of code with comment delimiters or to prefix every line in the section with a comment marker; this prevents it from being compiled or interpreted. Often done when the code is redundant or obsolete, but is being left in the source to make the intent of the active code clearer; also when the code in that section is broken and you want to bypass it in order to debug some other part of the code. Compare condition out, usually the preferred technique in languages (such as C) that make it possible.
The Jargon Dictionary - http://info.astrian.net/jargon/terms/c/comment_out.html

Good luck!!