From Longman Dictionary of Contemporary Englishmake certainmake certaina) CHECK/MAKE SUREto check that something is correct or true SYN make suremake certain (that) We need to make certain that it’s going to fit first. b) CERTAINLY/DEFINITELYto do something in order to be sure that something will happen SYN make suremake certain (that) Secure the edges firmly to make certain that no moisture can get in. → certain
Examples from the Corpus
make certain• Nicholas knelt, then lifted him to the base of the wall and knelt again, to make certain.• Contractors are working hard to make certain all the homes will be ready for occupation as soon as possible.• Reacher had made certain fine, illegal adjustments of the turbine.• This principle, then, makes certain general predictions about acquisition.• He watched her long enough to make certain she was breathing.• She's clearly intent on making certain that guests enjoy themselves.• Begin by making certain that the door itself is strong enough.• What position are they in to make certain the prisoners abide by the rules of their temporary release? 