调制 is a verb covering two main domains: (1) modulation in engineering, audio, or radio (e.g., 调制信号 'modulate a signal'), and (2) mixing or blending in cooking or medicine (e.g., 调制酱料 'prepare a sauce' or 调制中药 'concoct traditional medicine'). In informal contexts it can also mean 'to adjust' settings or conditions, but the core meaning involves modifying a substance or signal by combining or altering its components.