What's "a lack of" mean and what are the synonyms of it?

Native speaker’s answer
Rebecca
If there is a "lack" of something, it means that there's not enough of something. You could also use "shortage," "insufficient amount," and "deficit." Ex: There's a shortage of sanitary products in very rural areas. = There's a lack of sanitary products in very rural areas. Ex: The country has a lack of doctors, so they're recruiting people from overseas.