Press, bear, bear down, squeeze, crowd, jam mean to exert pressure upon something or someone continuously or for a length of time.
They are not close synonyms because of added implications and connotations which often give them distinct or specific senses.
Press fundamentally implies an effect involving a weighing upon or a steady pushing or thrusting and may suggest little more than this.
More often, however, the word is used in any of several extended senses in which it additionally implies such ideas as constraint or compulsion or urgency in driving or in prosecuting or importunity in urging or, especially in the intransitive, a pushing or shoving to an objective (as in great numbers or with speedy movement).
Bear (see also CARRY BEAR 3 ) implies the exertion of weight or of pressure upon another person or thing. Like press, the term has extended use; it and bear down may imply the achievement of any end consistent with the action of pressing down or heavily upon.
Squeeze usually implies the exertion of pressure on both sides or on all sides strongly enough and for a long enough time to accomplish a flattening, a crushing, a shaping, an emptying, or a compression.
Usually, however, the term carries an added implication that gives it an extended or specific meaning while often retaining its basic implication; sometimes it implies nothing more than an expression of affection, but at other times it implies such a different idea as extraction or eliciting with difficulty or extortion.
Squeeze is also susceptible to use even when there is no suggestion of exerting force on another but a clear suggestion of forcing someone, often oneself, or something into a space that is extremely small or is very circumscribed.
Crowd (see also PACK ) implies the exertion of pressure upon and usually suggests such a force as a number of persons or of things closely packed together.
Sometimes crowd implies pressure exerted by one or more persons in pushing or shoving through a crowd.
Jam in its most frequent meaning carries an implication of being wedged in so that pressure on all sides ensues and movement or escape is made impossible.
Sometimes, however, the term implies not pressure upon all sides but (as in reference to a gun, an engine, or a machine) the presence of an obstacle or an obstruction or the displacement of a part which prevents operation.