From inter- + placodal. <span class="searchmatch">interplacodal</span> (not comparable) between placodes...
From placode + -al. placodal (not comparable) Of or related to a placode <span class="searchmatch">interplacodal</span>...
interpigment interpillar interplacental interplacentomal interplacentome <span class="searchmatch">interplacodal</span> interplanar interplane interplanetary interplant interplasmid interplasmidic...