Machine
A tool mad of parts that is used to do some kind of work.
e.g. 'You can make clothes with a sewing machine.'
Challenge
Something that is hard to do.
e.g. 'A marathon is a challenge.'
Destination
The place you plan to go.
e.g. 'Our destination for the summer vacation is New York.'
Genius
Someone who is very smart.
e.g. 'My teacher is a genius!'
Future
A time that has not yet happened.
e.g. 'Tomorrow is in the future.'
Backward
To move towards the back.
e.g 'You can move some chess pieces backward.'
Captive
Not free to leave.
e.g. 'Caged animals are captive.'
Forward
To move ahead or to the front.
e.g. 'A sign can tell you to move forward.'
Concentrate
To think about what you are doing.
e.g. 'You have to concentrate when you are reading.'
Convince
To cause someone to agree with you
e.g. 'The woman tries to convince her husband.'