Of little importance; insignificant.
The tax is not payable on amounts below the de minimis limit of Â£100 per year.
The de minimis rules on import duty mean that alcohol for personal consumption is exempt from any charge.
Origin of de-minimis
From Latin dē minimīs (nōn cūrat lēx) (the law does not concern itself) with trifling matters dē of, about minimīs ablative pl. of minimum smallest (thing), least (thing) neuter of minimus smallest, least minimum