In this study, the densities of (aminomethanamide + 2-hydroxy-N,N,N-trimethylethanaminium chloride + water) and the solubilities of CO(2) in (aminomethanamide + 2-hydroxy-N,N,N-trimethylethanaminium chloride) with different varying mole fractions of water at temperatures of (303, 308, and 313) K are reported. The common name for (aminomethanamide + 2-hydroxy-N,N,N-trimethylethanaminium chloride) is reline. The densities are linear (AAD % is 0.22%) with respect to reline mass fraction at each temperature. The logarithms of Henry's law constants were correlated using the two-suffix Margules model as a function of reline mole fraction with an AAD of 3.44%. The results showed that CO(2) solubility in reline decrease with an increase water content. Hence water can serve as an antisolvent to strip CO(2) dissolved in reline. The absorption of CO(2) in (aminomethanamide + 2-hydroxy-N,N,N-trimethylethanaminium chloride + water) at low pressures is found to be endothermic at water content. However, the absorption becomes exothermic if the water content increases to a mole fraction greater than 0.769.