Regardless of N
This expression means 'regardless of' or 'irrespective of' and is used in formal contexts to indicate that the following action is not dependent on the noun mentioned.
Examples
天候いかんによらず、試合は行われる。
The match will be held regardless of the weather.
結果いかんによらず、全力を尽くした。
Regardless of the outcome, I did my best.
年齢いかんによらず、参加可能です。
Participation is possible regardless of age.
Quick check
The match will be held ___ of the weather.