first of all; to begin with; before anything else
Emphatic version of まず, used to stress that something should be done before anything else. Often used in instructions, advice, or when setting priorities.
See also: まず
Let's wash our hands first before eating.
First of all, let me introduce myself.
Before starting to cook, let's wash our hands first.
probably; most likely; almost certainly
Expresses a high degree of likelihood or near certainty. Often used when the speaker is confident about an outcome or assumption.
At this rate, it'll probably be fine.
I think he'll almost certainly pass.
more or less satisfactory; on the whole; reasonably
Indicates that something is acceptable or adequate, though not perfect. Used to give a moderate positive assessment.
The results were so-so, but on the whole I'm satisfied.
This hotel is reasonably comfortable.
Used to set a temporary plan or to move on from a topic, similar to 'for the time being' or 'in any case'. Often appears when the speaker wants to settle on a provisional course of action.
Let's see how it goes for now.
We'll talk about the details later; anyway, let's get started.
That's all for now; thank you in advance for your help.
With this plan, it will probably succeed.
This time's result can be said to be, on the whole, satisfactory.
とりあえず suggests a hasty, temporary measure taken without much thought, whereas まずは implies a more deliberate provisional choice.
一応 conveys that something is adequate for now in a tentative sense, close to まずは's meaning of 'reasonably satisfactory' in sense 3.
まずは introduces the first of several points to be covered, while 取り急ぎ signals apology for or acknowledgment of the haste behind the message itself.
Formed from the adverb まず (first) and the particle は, which adds emphasis or contrast. The combination has been lexicalized as a fixed adverbial expression.