A verb in The Etymologies of the 1930s appearing in its (Noldorin) infinitive form panno “to open, enlarge” under the root ᴹ√PAT (Ety/PAT). Given the glosses “to unfurl, spread out, open” for its Quenya cognate ᴹQ. panta-, I would assume panna- means “enlarge” in the sense “✱expand”.
Neo-Sindarin: I currently recommend using ᴺS. panna- as a Neo-Sindarin verb for “arrange; put” inspired by G. panta-. Unfortunately, this conflicts with panna- “open”. In many cases the meaning should be clear from context based on the object of the verb, such as panno i fend “open the door” vs. panno i vegil bo i hardh “put the sword on the table”. Where things are ambiguous, I think the adverb ed “out” can be used to make the sense “open” more clear, as panno ed i golch “open (out) the box” vs. panno i golch v’i tham “put the box in the room” vs. panno ed i golch v’i tham “open (out) the box in the room”. Compare also intrasitive S. edra- “open (out)”.
A noun appearing as N. pann “courtyard” in The Etymologies of the 1930s under the root ᴹ√PAD, a cognate to ᴹQ. panda “enclosure” (Ety/PAD).
Conceptual Development: The Gnomish Lexicon of the 1910s had G. paga “court, paved floor” derived from the early root ᴱ√PAKA having to do with pavement (GL/63).
Neo-Sindarin: For purposes of Neo-Sindarin the word pann is often adapted as ᴺS. pand “courtyard” as suggested in HSD (HSD), in keeping with the principle that “nd became nn usually ... but remained nd at the end of fully accented monosyllables” (LotR/1115).