-oid, -oidal, -oidism, -odic

(Greek: a suffix; like, resembling, similar to, form)

teratoid
Monstrous, resembling a monster (denotes any malformed animal, including man, that deviates grotesquely from the norm with the implication that the result is hideous, frightening, and revolting. Anyone who has viewed "freak shows" at circuses or carnivals has been exposed to teratological experiences.
testoid
Resembling a testis.
tetraploid
thalassoid
Freshwater organisms resembling, or originally, marine forms; halolimnic (marine organisms modified to live in fresh water).
thanatoid
Resembling death; apparently dead; deathlike.
therioid
Like an animal.
theroid
Like or having the form of a brute; of bestial nature or character.
A man considers himself to be a raging bull.
thromboid
thylakoid
Any of a group of chlorophyll-containing membranous structures resembling sacs in which photosynthesis takes place.

Thylakoids are stacked one on top of the other in the chloroplast layers grana (in which the green pigment chlorophyll is contained) of most plants.

thyrohyoid
thyroid
tigroid
Resembling a tiger or tiger's skin; marked like a tiger; having the characteristics of a tiger (fierce, aggressive, etc.).
toroid (s) (noun), toroids (pl)
1. In geometry, a surface that is created by the rotation of any closed curves; such as, a circle or ellipse around an axis in its plane.
2. In electricity, an electromagnetic coil that is wound on a ring of circular cross-sections.
toxoid
trapezoid
1. In math, a quadrilateral that has two parallel sides.
2. A small bone in the wrist near the metatarsal bone that connects with the index finger.

Inter-related cross references, directly or indirectly, involving word units dealing with "form, shape, appearance": eido-; figur-; form-; icono-; ideo-; imag-; morpho-; typo-.