Here we have two minor errors in the early RLDS text: (1) lyings to lying in the 1874 edition (and copied as such into the following 1892 edition), and (2) revilings to revelings in the 1892 edition. In the 1908 RLDS edition, the correct readings were restored to the RLDS text. The discussion under Alma 12:1 and 12:3 shows that for each case of lying(s) and deceiving(s), the critical text will accept the number of the earliest textual source, thus “against all lyings and deceivings” here in Alma 16:18. Of course, this entire passage contains plural forms except for one word that can occur only in the singular (namely, malice). For other examples in this chapter where the 1874 RLDS edition replaced plurals with singulars, see under verses 19 and 21.
As far as revilings is concerned, the preceding conjoined nouns all deal with mistreating others. The 1892 revelings is, of course, inappropriate here. Moreover, there are no examples of the verb revel in the Book of Mormon. On the other hand, revile is fairly frequent in the text; there is, in fact, one other example of the plural revilings: “fear ye not the reproach of men neither be ye afraid of their revilings” (2 Nephi 8:7, quoting Isaiah 51:7).
Summary: Maintain in Alma 16:18 the original plural form lyings and the nominalized verbal noun revilings.