1 : a small object produced by a plant from which a new plant can grow
a packet of sunflower seeds
He planted/sowed the seeds three inches apart.
(US) apple/orange seeds [=(Brit) pips]
She raked the grass seed into the soil.
She grows her plants from seed. [=by planting seeds rather than by some other method]
— see color picture on THIS PAGE
2 [count] : the beginning of something which continues to develop or grow
Her comment planted/sowed a seed of doubt in his mind. [=caused him to begin to have doubts]
The government's policies planted/sowed the seeds of war/destruction. [=created a situation that led to war/destruction]
3 [count] : a player or team that is ranked as one of the best in a competition (such as a tennis tournament) in order to be sure that the best players or teams do not play against each other in the early part of the competition
The top seed won the tournament.
Our team is the number one seed.
She is ranked as the third seed.
a literary : all the children, grandchildren, etc., of a particular man
the seed of Abraham
b old-fashioned + humorous : a man's semen
a man spreading his seed [=fathering many children]
go to seed or run to seed
1 : to produce seeds
The flowers will go to seed and spread.
The plant runs to seed rapidly in hot weather.
2 : to become less attractive, effective, etc., because of age or lack of care
He let himself go to seed after he lost his job.