teddy vs teddy bear

teddy and teddy bear both are nouns.

Word	Noun	Adjective	Verb	Adverb
teddy	Yes	No	No	No
teddy bear	Yes	No	No	No

As nouns, teddy and teddy bear are synonyms defined as:

teddy and teddy bear: plaything consisting of a child's toy bear (usually plush and stuffed with soft materials)

teddy (noun)	teddy bear (noun)
a woman's sleeveless undergarment	plaything consisting of a child's toy bear (usually plush and stuffed with soft materials)
plaything consisting of a child's toy bear (usually plush and stuffed with soft materials)