The following adjectives are used to describe sizes and shapes:

	Adjective	Meaning	Example
1.	small	Not large in size	small pink sock
2.	tiny	Very small	tiny lump
3.	big	Large in size	big bugs
4.	little	Small	little bugs
5.	thick	Broad, something grows close together and in large amounts	thick treetops
6.	giant	Extremely large	giant spiders
7.	huge	Very large	huge trees
8.	wide	It measures a large distance from one side to the other	wide tree trunks
9.	long	It measures a great distance from one end to the other	long green snake
10.	biggest	The largest	biggest predator

Reference: Cambridge Dictionaries Online, Collins Cobuild Advanced Learner's English Dictionary