Following are all the underside like words, in the list below.
UNDERSURFACE
100% like underside
BOTTOM
99.85% like underside
UNDERNEATH
66.72% like underside
BELOW
66.72% like underside
HINDWING
66.64% like underside
FUSE
66.62% like underside
UNDERWEAR
66.56% like underside
BELLY
66.56% like underside
REAR
66.56% like underside
ABDOMEN
66.56% like underside
SETBACK
66.54% like underside
UNDERBELLY
66.39% like underside
COUCHING
66.34% like underside
TUMMY
66.32% like underside
WOMB
66.24% like underside
GUT
66.24% like underside
STOMACH
66.24% like underside
ABDOMINAL
66.21% like underside
BACKHAND
66.04% like underside
SET-BACK
33.44% like underside
UPPERSIDE
33.44% like underside
BACKSIDE
33.44% like underside
SURFACE
33.44% like underside
BENEATH
33.44% like underside
SIDE
33.44% like underside
UNDERCARRIAGE
33.44% like underside
UNDERPART
33.44% like underside
TOPSIDE
33.44% like underside
PROTRUDING
33.44% like underside
EDGES
33.44% like underside
OVERSIDE
33.44% like underside
FRONT
33.44% like underside
ONTO
33.44% like underside
INSIDE
33.44% like underside
UPPER
33.44% like underside
CLASPERS
33.44% like underside
SIDES
33.44% like underside
UNDERSURFACES
33.44% like underside
INSIDES
33.44% like underside
UPPERWING
33.44% like underside
OUTSIDES
33.44% like underside
EXTERIOR
33.44% like underside
OUTER
33.44% like underside
CREVICE
33.44% like underside
UNDERBODY
33.44% like underside
FLECKING
33.44% like underside
PROTRUSION
33.44% like underside
EDGE
33.44% like underside
UNDERSTRUCTURE
33.44% like underside
COATING
33.44% like underside
CREVICES
33.44% like underside
HEADPLATE
33.44% like underside
PERIDIUM
33.44% like underside
BOTTOMS
33.44% like underside
OVERHANGING
33.44% like underside
CARAPACE
33.44% like underside
DORSAL
33.44% like underside
INDUSIUM
33.44% like underside
INNARDS
33.44% like underside
DORSUM
33.44% like underside
CLASPER
33.44% like underside
LONGERON
33.44% like underside
MIDPORTION
33.44% like underside
NEARSIDE
33.44% like underside
TERGAL
33.44% like underside
UPTURNED
33.44% like underside
ROOF
33.44% like underside
OUTERMOST
33.44% like underside
ATOP
33.44% like underside
UNDERDECK
33.44% like underside
PROTRUSIONS
33.44% like underside
PLATE
33.44% like underside
MIDVEIN
33.44% like underside
SURFACES
33.44% like underside
FLOORBOARD
33.44% like underside
PROTHORAX
33.44% like underside
SOUTHMOST
33.44% like underside
UNDERSTEP
33.44% like underside
UNDERPORTION
33.44% like underside
UNDERSECTION
33.44% like underside
UNDERLAYER
33.44% like underside
SUBSURFACE
33.44% like underside
UNDERFRINGE
33.44% like underside
UNDERCUTTING
33.44% like underside
UNDERLIER
33.44% like underside
BACK END
33.44% like underside
SUBTERRAIN
33.44% like underside
UNDERSEND
33.44% like underside
DOWNSTACK
33.44% like underside
SUBDEPOSIT
33.44% like underside
UNDERSWELL
33.44% like underside
UNDERSONG
33.44% like underside
UNDERLEVEL
33.44% like underside
LOWER BODY
33.44% like underside
UNDERSCORING
33.44% like underside
UNDERFRAMEWORK
33.44% like underside
UNDERSOCIETY
33.44% like underside
UNDERGOVERNMENT
33.44% like underside
UNDERFILTER
33.44% like underside
UNDERCOVERING
33.44% like underside