Trial on air is unreliable and totally unreasonable (10)

I believe the answer is:

irrational

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'totally unreasonable' is the definition.
'irrational' can be an answer for 'unreasonable' (similar in meaning). I am not certain of the 'totally' bit.

'trial on air is unreliable' is the wordplay.
'is unreliable' indicates an anagram (an unreliable or inaccurate spelling).
'trial'+'on'+'air'='trialonair'
'trialonair' is an anagram of 'IRRATIONAL'.

'and' acts as a link.

Can you help me to learn more?

(Other definitions for irrational that I've seen before include "Unreasonable" , "Illogical" , "Not logical" , "Crazy" , "Kind of numbers" .)

I've seen this clue in The Irish Times.

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