Children's Illustrated Dictionary.

a b c d e f g h i j k l m n o p q r s t u v w x y z

Oo

oak
oaks noun

a large deciduous tree that
has fruit called acorns.
Oak wood is often
used for making
furniture (see
tree on page 223).

oak leaf

oar
oars noun
a long pole
with a wide,
flat end used
for rowing
a boat.
N say or

oasis
oases noun

a place in the desert where
there is water and where
plants and trees can grow.

N say oh-ay-sis

oats
noun
a type of cereal
crop grown on farms.
Oats are used to
make food and to
feed cattle, horses,
and other animals.

obey

obeys obeying

obeyed verb

to do something

that someone

tells or orders

you to do.

She taught the dog to obey

her commands.

N opposite disobey

obedient adjective

object

objects noun

anything you can see

or touch that isn’t alive.

N say ob-jekt

object

objects objecting objected verb

to dislike or disagree

with something.

He objected to people dropping

litter in the street.

N say ub-jekt

oblong

adjective

longer than it is wide, with

sides nearly parallel.

An oblong box.

oblong noun

observatory

observatories noun

a building from which people

observe stars, the planets,

and the weather, using

powerful telescopes.

observe

observes observing observed

verb

to watch something.

observation noun

obstacle

obstacles noun

a thing that blocks your way.

He had to jump over 10

obstacles to win the race.

obstinate

adjective

difficult to persuade.

He was very obstinate and

refused to pick up his room.

obstinately adverb

obvious

adjective

easy to see or understand.

N say ob-vee-us

obviously adverb

occasion

occasions noun

1 a special event.

The park opening was

a grand occasion.

2 a time when

something happens.

I have flown in an airplane

on two occasions.

occupation

occupations noun

the work that someone does

to earn a living.

occupy

occupies occupying occupied

verb

1 to be busy.

I was occupied with my book

when the doorbell rang.

2 to take up a space or live

in a place.

The company occupied the top

two floors of the building.

3 to control a place by force.

The army occupied the city.

occur

occurs occurring occurred verb

1 to happen or exist.

When did the problem occur?

2 to come into your mind.

That never occurred to me.

occur

obstruct

obstructs obstructing

obstructed verb

to block or to prevent

something

or someone

from passing.

She obstructed his path.

obstruction noun