The Collaborative International Dictionary of English v.0.48:

Trellis \Trel"lis\, n. [OE. relis, F. treillis, fr. treille vine
   arbor, fr. L. tricla, triclea, triclia, a bower, arbor,
   summer house.]
   A structure or frame of crossbarred work, or latticework,
   used for various purposes, as for screens or for supporting
   plants.
   [1913 Webster]

WordNet (r) 3.0 (2006):

trellis
    n 1: latticework used to support climbing plants [syn:
         trellis, treillage]
    v 1: train on a trellis, as of a vine

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

Trellis

   1. An object-oriented language from the University of
   Karlsruhe(?) with static type-checking and encapsulation.

   2. An object-oriented application development system from
   DEC, based on the Trellis language.  (Formerly named Owl).

   E-mail: Jerry Smith 

   ["Persistent and Shared Objects in trellis/owl", P. O'Brien et
   al, Proc 1986 IEEE Workshop on Object-Oriented Database
   Systems, IEEE, NY 1986].