【Crush】 , 【mash】 , 【smash】 , 【bruise】 , 【squash】 , 【macerate】  are comparable when they mean to reduce or be reduced to a pulpy or broken mass.

【Crush】 implies a compressing between- two hard or resistant surfaces that succeeds, usually, in destroying the shape and integrity of the mass; the result depends on the texture of what is crushed, whether it is permanently deformed and destroyed, broken into fragments, or capable of springing back into shape.

【Mash】 implies the beating or pounding of something, often deliberately, to a soft pulp; in this sense 【mash】 may come close to 【crush】 in meaning, but it is more often used in reference to the preparation of certain vegetables and fruits in the kitchen by similar means.

【Smash】 carries a stronger implication of violence in implying a force that shatters or batters; it also often suggests the uselessness for all purposes of what is smashed.

【Bruise】 , though more commonly used in reference to an injury of the flesh, also carries a sense related to that of  【crush】 , 【smash】 , or 【mash】 in which it implies the pressing or beating of something so as to break it down with the effect of setting the juices running or of softening the fibers.

【Squash】 differs from the preceding words chiefly in its applicability to objects that are very soft (as through overripeness or immaturity)or that require little effort to 【crush】 by pressure.

【Macerate】  is used chiefly in reference to a process of steeping something in a liquid so as to soften or detach its fibers or to wear away its soft parts; the softening or detachment of fibers is chiefly emphasized, and 【macerate】 often refers to a step in an industrial process or to a part of a digestive process.

The term may, however, imply a wearing away of the soft part from whatever cause; it particularly suggests a wasting away of the body (as through fasting or worry).