The Collaborative International Dictionary of English v.0.48:

Concatenate \Con*cat"e*nate\ (k[o^]n*k[a^]t"[-e]*n[=a]t), v. t.
   [imp. & p. p. Concatenated; p. pr. & vb. n.
   Concatenating.] [L. concatenatus, p. p. of concatenare to
   concatenate. See Catenate.]
   To link together; to unite in a series or chain, as things
   depending on one another.
   [1913 Webster]

         This all things friendly will concatenate. --Dr. H.
                                                  More
   [1913 Webster]

WordNet (r) 3.0 (2006):

concatenate
    v 1: combine two strings to form a single one
    2: add by linking or joining so as to form a chain or series;
       "concatenate terms"; "concatenate characters"

The Free On-line Dictionary of Computing (19 January 2023):

concatenate

    To join together two or more files or lists to form
   one big one.

   The Unix cat command can be used to concatenate files.

   (1995-12-22)