1.  guava(n = noun.plant) psidium littorale, strawberry guava, yellow cattley guava - small tropical shrubby tree bearing small yellowish fruit;
is a kind of fruit tree
is a member of genus psidium, psidium

2.  guava(n = noun.plant) guava bush, psidium guajava, true guava - small tropical American shrubby tree; widely cultivated in warm regions for its sweet globular yellow fruit;
is a kind of fruit tree
has parts: guava
is a member of genus psidium, psidium

3.  guava(n = noun.food) - tropical fruit having yellow skin and pink pulp; eaten fresh or used for e.g. jellies;
is a kind of edible fruit
is a part of guava, guava bush, psidium guajava, true guava

   A tropical tree, or its fruit, of the genus Psidium. Two varieties are well known, the P. pyriferum, or white guava, and P. pomiferum, or red guava. The fruit or berry is shaped like a pomegranate, but is much smaller. It is somewhat astringent, but makes a delicious jelly. [1913 Webster]

guava, n.
1 a small tropical American tree, Psidium guajava, bearing an edible pale yellow fruit with pink juicy flesh.
2 this fruit.

Etymology:
Sp. guayaba prob. f. a S. Amer. name

brazilian guava, cattley guava, guava bush, pineapple guava, purple strawberry guava, strawberry guava, true guava, yellow cattley guava