Lonken Lonkin Lonke
The handwritten name on the front page of the passport looks roughly like this.
or 
. Transliterating the family name, one obtains Lonkin, if we ignore the final
character. The 'i' would be sounded like 'ee' in seen. 'kin' is a common Russian name ending, as in Pushkin.
The feminine form is 'kina'. The final character
is a 'ch'. 
translates to 'lawn'. In the portions of the
passport written by officials, the name is always written Lonke.
Recently (June 2020) I became aware of an Israeli cousin named Gali Ron who has shared a family tree with earlier Lonke relatives and their descendants. The earlier people were all living in Grodno. Josef, Solomon's father, is called Josel. Gali is a descendant of Zilpah Lonke.
The Yiddish word for London is לאָנדאָן The two אָ are currently pronounced as 'uw' or 'aw' or 'ow' or in between,
| Aron Lonke | ||||||
| Birko Lonke 1788-1852 | ||||||
| Simkel Lonke 1822-1852 | ||||||
| Yankel Lonke 1850 - | ||||||
| Shloima Lonke 1800-1854 | ||||||
| Josel Lonke 1832- | ||||||
| +Minek Lonke 1838-1911 | ||||||
| Solomon Landowne 1857-1934 | ||||||
| +Anna Rachla Sulcas 1861-1931 | ||||||
| children | ||||||
| Harris (Aharon Tzvil) Lando 1866-1939 | ||||||
| +Minnie Lachman 1872-1934 | ||||||
| children | ||||||
| Helen Lonke 1868-1941 | ||||||
| +Harry Kalisky 1866-1938 | ||||||
| children | ||||||
| Abram Lonke 1834- | ||||||
| Pinkhus Lonke 1848 - | ||||||
| +Yenta | ||||||
| Josel Lonke 1873-1940 | ||||||
| +Rachel 1882-1942 | ||||||
| Solomon Lonke 1876- | ||||||
| +Ester Kokhman 1878- | ||||||
| children | ||||||
| Aron Lonke 1877- | ||||||
| Dveira Lonke 1880- | ||||||
| Zilpah Lonke 1882-1944 | ||||||
| +Yaakov Mosha Shvarts 1874-1944 | ||||||
| children | ||||||
| +Malka Rivkind 1860-1940 | ||||||
| Yakov Lonke 1893-1941 | ||||||
| +Rachel Gurevitz 1890-1941 | ||||||
| children | ||||||
| Shebach Shola Lonke 1900-1944 | ||||||
| +Faniga Kalich 1904- | ||||||
| children | ||||||
The Dictionary of American Family Names Patrick Hanks 2003, 2006 says the name Lonkin is Jewish (from Belarus): metronymic from the Yiddish female personal name Sonke, derived from an eastern Slavic pet form of Sofiya, equivalent of Sophie, with the eastern Slavic possessive suffix -in.
As it happens, lonke is yiddish for meadow or lawn and is mentioned in a song Yidl Mitn Fidl from a famous 1936 movie by the same name, filmed in Kazimierz Dolny, Republic of Poland, about 150 miles southwest of Grodno, which was also in the Republic of Poland at that time. That song page has the word in hebrew which I have copied below.
