We report on the timing observations of the millisecond pulsar PSR J2055+3829 originally discovered as part of the SPAN512 survey conducted with the Nançay Radio Telescope . The pulsar has a rotational period of 2.089 ms , and is in a tight 3.1 hr orbit around a very low mass ( 0.023 \leq m _ { c } \lesssim 0.053 M _ { \odot } , 90 % c.l . ) companion . Our 1.4 GHz observations reveal the presence of eclipses of the pulsar ’ s radio signal caused by the outflow of material from the companion , for a few minutes around superior conjunction of the pulsar . The very low companion mass , the observation of radio eclipses , and the detection of time variations of the orbital period establish PSR J2055+3829 as a ‘ black widow ’ ( BW ) pulsar . Inspection of the radio signal from the pulsar during ingress and egress phases shows that the eclipses in PSR J2055+3829 are asymmetric and variable , as is commonly observed in other similar systems . More generally , the orbital properties of the new pulsar are found to be very similar to those of other known eclipsing BW pulsars . No gamma-ray source is detected at the location of the pulsar in recent Fermi -LAT source catalogs . We used the timing ephemeris to search ten years of Fermi Large Area Telescope ( LAT ) data for gamma-ray pulsations , but were unable to detect any . This non-detection could be a consequence of the pulsar ’ s large distance compared to those of known gamma-ray millisecond pulsars outside of globular clusters . We finally compared the mass functions of eclipsing and non-eclipsing BW pulsars and confirmed previous findings that eclipsing BWs have higher mass functions than their non-eclipsing counterparts . Larger inclinations could explain the higher mass functions of eclipsing BWs . On the other hand , the mass function distributions of Galactic disk and globular cluster BWs appear to be consistent , suggesting , despite the very different environments , the existence of common mechanisms taking place in the last stages of evolution of BWs .