The phrase "more off-hand" can be substituted with several synonyms, including nonchalant, casual, indifferent, unpremeditated, and spontaneous. Nonchalant describes a lack of concern or interest, while casual suggests a relaxed or informal attitude. Indifferent means without a preference or emotional investment, while unpremeditated implies that something is impromptu or unplanned. Spontaneous refers to something that arises naturally or without forethought. All of these synonyms can be used interchangeably depending on the context in which "more off-hand" is being used. It is important to consider the tone and intended meaning of the sentence in order to choose the appropriate synonym.