  The multiwavelength data of nuclear transient AT2018dyk, initially discovered
as a changing-look low-ionization nuclear emission-line region (LINER) galaxy,
has been revisited by us and found being in agreement with a tidal disruption
event (TDE) scenario. The optical light curve of AT2018dyk declines as a
power-law form approximately with index -5/3 yet its X-ray emission lags behind
the optical peak by $\sim140$ days, both of which are typical characteristics
for TDEs. The X-ray spectra are softer than normal active galactic nuclei
(AGNs) although they show a slight trend of hardening. Interestingly, its
rising time scale belongs to the longest among TDEs while it is nicely
consistent with the theoretical prediction from its relatively large
supermassive black hole (SMBH) mass ($\sim10^{7.38} M_{\odot}$). Moreover, a
prominent infrared echo with peak luminosity
$\sim7.4\times10^{42}~\text{erg}~\text{s}^{-1}$ has been also detected in
AT2018dyk, implying an unusually dusty subparsec nuclear environment in
contrast with other TDEs. In our sample, LINERs share similar covering factors
with AGNs, which indicates the existence of the dusty torus in these objects.
Our work suggests that the nature of nuclear transients in LINERs needs to be
carefully identified and their infrared echoes offer us a unique opportunity
for exploring the environment of SMBHs at low accretion rate, which has been so
far poorly explored but is crucial for understanding the SMBH activity.
