ample

As an adjective ample

is large; great in size, extent, capacity, or bulk; spacious; roomy; widely extended.

As an adverb unduly is

undeservedly, not warranted.

Sincere is a related term of ample.

As adjectives the difference between sincere and ample

is that sincere is sincere while ample is large; great in size, extent, capacity, or bulk; spacious; roomy; widely extended.

Immense is a related term of ample.

As adjectives the difference between immense and ample

is that immense is huge, gigantic, very large while ample is large; great in size, extent, capacity, or bulk; spacious; roomy; widely extended.

Ample is a related term of thick.

As adjectives the difference between ample and thick

is that ample is large; great in size, extent, capacity, or bulk; spacious; roomy; widely extended while thick is relatively great in extent from one surface to the opposite in its smallest solid dimension.

As an adverb thick is

in a thick manner.

As a noun thick is

the thickest, or most active or intense, part of something.

As a verb thick is

(archaic|transitive) to thicken.

Prodigal is a synonym of ample.

As adjectives the difference between prodigal and ample

is that prodigal is wastefully extravagant while ample is large; great in size, extent, capacity, or bulk; spacious; roomy; widely extended.

As a noun prodigal

is a prodigal person, a spendthrift.

Unconfining is a related term of ample.

As adjectives the difference between unconfining and ample

is that unconfining is not confining while ample is large; great in size, extent, capacity, or bulk; spacious; roomy; widely extended.

Genuine is a related term of ample.

As adjectives the difference between genuine and ample

is that genuine is belonging to, or proceeding from the original stock; native; hence, not counterfeit, spurious, false, or adulterated; authentic; real; natural; true; pure while ample is large; great in size, extent, capacity, or bulk; spacious; roomy; widely extended.