I can think of several.
Some four letter words ending in L are:ballbellbillboilbullcallcellcoilcoolcurlearlfailfallfeelfellfillfoilfoolfoulfowlfullgallgoalgillgullhallhailheelhellhillhulljelljailjowlkeelkilllolllullmallmailmealmillmoilmullnailnullpailpallpeelpillpollpoolpurlrailreelrollsailsealsellsillsoiltailtalltealtelltoiltooltollveilwailwallwealwellwillyellzeal
unnatural
Arrival, alcohol
shawl
compelconsulcorralcarnal
literal
shallow shallow
The obvious word is "stellar." The transposition is "staller."
"Lucky" is a five letter word beginning with l
Some four letter words ending in L are:ballbellbillboilbullcallcellcoilcoolcurlearlfailfallfeelfellfillfoilfoolfoulfowlfullgallgoalgillgullhallhailheelhellhillhulljelljailjowlkeelkilllolllullmallmailmealmillmoilmullnailnullpailpallpeelpillpollpoolpurlrailreelrollsailsealsellsillsoiltailtalltealtelltoiltooltollveilwailwallwealwellwillyellzeal
curtail
unnatural
wonderful
That's wonderful.
Arrival, alcohol
ladlaidlandlatchedlayeredleadledleasedlaughedleopardleashedleotardloanedloathedlatheredlovedlidlickedlackedliftedlessenedlappedliedlikedlivedlinedlingeredlordloadlocatedlonged
shawl