"Serious criminality" refers to activities that are considered very illegal and harmful to society. It includes crimes that are severe, dangerous, or have a significant impact on people's safety and well-being. Full definition
At the time he entered the plea, his counsel had not informed him that such a conviction would make him inadmissible to Canada on grounds of serious criminality pursuant to s. 36 (1)(a) of the Immigration and Refugee Protection Act; nor had his counsel discussed the defence of entrapment with him. (canadianlawyermag.com)
According to the Immigration law, a permanent resident or foreign national is inadmissible to Canada for serious criminality if they are convicted in Canada of an offence punishable by a maximum term of imprisonment of at least 10 years or of an offence for which a term of imprisonment of more than 6 months was imposed. (mtcsalc.org)
It's like, for example, for serious offences, it is not serious criminality as it is in this bill. (sencanada.ca)