||Recently, the MiniBooNE experiment at Fermilab has updated the results with increased data and reported an excess of 560.6 +/- 119.6 electronlike events (4.7 sigma) in the neutrino operation mode. In this paper, we propose a scenario to account for the excess where a Dirac-type sterile neutrino, produced by a charged kaon decay through the neutrino mixing, decays into a leptophilic axionlike particle (lALP) and a muon neutrino. The electron-positron pairs produced from the lALP decays can be interpreted as electronlike events provided that their opening angle is sufficiently small. In our framework, we consider the lALP with a mass m(a) = 20 MeV and an inverse decay constant c(e)/f(a) = 10(-2) GeV-1, allowed by the astrophysical and experimental constraints. Then, after integrating the predicted angular or visible energy spectra of the lALP to obtain the total excess event number, we find that our scenario with sterile neutrino masses within 150 MeV less than or similar to mN less than or similar to 380 MeV (150 MeV less than or similar to m(N) less than or similar to 180 MeV) and neutrino mixing parameters between 10(-10) less than or similar to vertical bar U-mu 4 vertical bar(2) less than or similar to 10(-8) (3 x 10(-7) less than or similar to vertical bar U-mu 4 vertical bar(2) less than or similar to 8 x 10(-7)) can explain the MiniBooNE data.