英和和英

copulate with

an exact duplicate

a duplicated thing

is/are duplicated

raise to the second power

combine by multiplication

mate with

mate with

to make even or uniform

a condition in which an action is very difficult to carry out

to publish a work in a series

undergo polymerization

to put two sheets together―put one sheet on another―put one sheet on top of another

to combine two classes―（団体なら）―unite two parties

take sides with

to pair―twin

overlap

to be consistent

（賃銀なら）to charge an extra―（配当なら）―give a bonus

to use a thing for more than one purpose

undergo conjugation

to neglect a matter―slight a matter―let things slide

to agree on other's opinion, not having one's own

string together

have a double

be parallel to

bring into alignment with

meet one's double

to recombine that

to double oneself