Aid can be a verb or a noun. Help can also be a verb or a noun. That’s convenient because they are synonyms in at least one sense of each of the noun and verb forms.
What is that sense? A dictionary can help or aid you to discover that. A dictionary can also provide you with aid or help in discovering that sense. Did that answer it for you?
To aid, i.e., the verb, can also mean to facilitate or to help to facilitate an outcome. For example, one might say, “His embezzling of widows and orphans aided his early and rich retirement.”
All I can say to that is I wish I believed there was a god, a heaven and a hell, because I’d love for the embezzler to experience the latter. That’s the drawback of being an atheist. There are limits to the punishments that I can expect to be imposed in a merciful, just society.
The noun aid can also refer to someone or something who or that is someone’s helper. For example a nurse’s aid is someone who is not a nurse himself or herself, but who helps a nurse or nurses. And a hearing aid is a device that helps people to hear. I said, A HEARING AID IS A DEVICE THAT HELPS PEOPLE TO HEAR.
One important question that the dictionary doesn’t answer is, how do I get an aid without having to dole out any of my own money to do so? Indolent minds want to know.
The New Penguin English Dictionary (1986) says that British people also use the noun aid to mean, “for the purpose of,” as in, “what’s this in aid of?”
This is one of those cases where Canadians (such as myself) use the British idiom. I thought everyone used aid that way.
I’m a marketing communications writer by trade. Many of my clients are American companies. If the dictionary is right about this sense of aid being primarily British (and Canadian) I hope I’ve never used aid that way in anything I’ve written for my American clients. They might think I’m an idiot. Then again, I’m not at all certain they don’t think that anyway. Fortunately, they seem to like my writing nevertheless.