Lincolnshire Police received a report of a man with a suspected stab wound at a property in Grosvenor Road at 9.26am today (Friday).
Paramedics attended but the man, aged 47, died at the scene.
A 42-year-old woman was shortly arrested in the local area on suspicion of murder. She remains in custody and will be questioned in due course.
Officers remain at the scene and investigations are ongoing, and police have launched a murder investigation.
A spokesman for Lincolnshire Police said: “We would like to hear from anyone who may have CCTV, dashcam, or witnessed anything suspicious.
“Anyone with any information can call us on 101, quoting incident 97 of 2 December.”
Further information will be released in due course.