Used as a connecting word to mean "if", "supposing", or "in case".

to suppose, assume, or presume something as true; to hypothesize; to create a fictional or imaginary scenario

a hypothesis, postulate, or conjecture in scientific research or logical reasoning that has yet to be proven; also called a 假说 jiǎ​shuō

to set up or provide for temporarily or provisionally, as in a simple meal or equipment