Center letter: a
Outer letter: d g h i l n
Answers (69):
  gladhanding
  handling
  highland
  adding
  addling
  again
  aging
  aiding
  ailing
  alga
  algal
  align
  aligning
  anal
  angina
  angling
  annal
  dahlia
  dandling
  dang
  dangling
  dial
  dialing
  gadding
  gaga
  gagging
  gain
  gaining
  gala
  galangal
  gall
  galling
  gang
  ganging
  gangland
  ganglia
  gangling
  glad
  gladhand
  gland
  glia
  haggling
  hail
  hailing
  halal
  hall
  hand
  handing
  hang
  hanging
  hangnail
  inhaling
  inlaid
  inland
  lading
  ladling
  lagging
  laid
  lain
  lanai
  land
  landing
  naan
  nada
  nagging
  naiad
  nail
  nailing
  nana