"ligation" is the verb-form (i.e. making something with/into ligatures).
replyI'm not sure however that the verb form makes all that much sense in the context the website uses it...
English is great at exceptions, but I'm nearly sure anything ending in -ation is a noun. Ligation certainly is.
replyLigation is (among other things) the act of applying a ligature. So it does make sense.
Yes, technically it is a deverbal noun, but I couldn't put my finger on that term at the time
reply