- firstly
- adverb (sentence adverb) used to say that the fact or reason that you are going to mention is the first one and will be followed by others: Firstly, I would like to thank everyone who has contributed to this success. USAGE NOTE: FIRSTLY WORD CHOICE: firstly, first (of all), in the first place, to start/begin with, at first, in the beginning Firstly/first (of all)/in the first place/to start with/to begin with are often used to introduce a series of reasons, ideas, remarks etc: There are three reasons why I don't like him: first(ly)/to start with he's rude, second(ly) he's a liar, and third(ly)/finally he owes me money. You use first (of all) (NOT firstly) to introduce a series of actions, often in order of time: First of all I get dressed, next I bring in the paper, then I fix breakfast. At first can only be used for a period of time, often when you are comparing it with a later period. To start/begin with and in the beginning can be used in this way too: You'll find it difficult at first/to begin with, but later/soon it'll get easier.
Longman dictionary of contemporary English. 2004.